The earliest period of development in animals is governed not at the level of transcription but by the activation of stored maternal mRNA for translation. Activation does no occur simultaneously for all stored mRNAs but rather sequentially and in several different patterns. Understanding of the earliest events in human life, then requires understanding how specific sequences or sequence classes are activated, used and subsequently degraded. A major cis-acting element has already been identified, the cytoplasmic polyadenylation sequence. It is the goal of the proposed work to expand our understanding of this process using a combined computational and experimental approach, using primarily the mouse as an experimental model organism. For a comparative genomics approach parallel processes in the zebrafish will also be explored. The specific aims of the project will test the hypothesis that additional cis-acting elements exist which act singly or combinatorially to control activation of translation. In addition, we will exam the role of a novel form of a major translation control protein, elF4E, in this process.